Lithium electrode for electrical energy storage device

Claim 2

A composite negative lithium electrode structure for an electrical energy storage device wherein said composite electrode structure comprises: an alloy of lithium, silicon, and iron having the empirical formula Li x SiFe y , where x has a value from 1 to 5 and y has a value from 0.125 to 1, and a current-collecting matrix supporting said alloy and in intimate contact therewith.

Claim 3

The electrode structure of claim 1, wherein x has a value from 4 to 5 and Fe has a value from 0.125 to 0.5.

Claim 4

The electrode structure of claim 1, wherein said supporting current-collecting matrix includes a porous substrate formed from metal fibers.

Claim 5

The electrode structure of claim 3, wherein said metal fibers are iron fibers having a diameter of from about 10 to 200 microns.

Claim 6

The electrode structure of claim 3, wherein said metal fibers are nickel fibers having a diameter of from about 10 to 200 microns.

Claim 7

The electrode structure of claim 3, wherein said metal fibers are titanium fibers having a diameter of from about 10 to 200 microns.

Claim 8

The electrode structure of claim 1, wherein the supporting current-collecting matrix comprises a porous metal substrate impregnated with said alloy and further includes a perforate container enclosing the porous metal substrate.

Claim 9

The electrode structure of claim 1, wherein the supporting current-collecting matrix comprises a unitary multi-cell structure, including: a plurality of wall members having edges and axially extending surfaces which form a plurality of cells having at least one open end and a cell cross-sectional open area of at least about 0.04 cm 2 , said edges of said wall members and the open end of said cells being aligned in a common plane to form a planar surface, the axially extending surfaces of said wall members being substantially perpendicular to said planar surface; said alloy being disposed in said cells; and an electrolyte-permeable member affixed to said wall members and covering the open end of said cells for retaining said alloy in said cells.

Claim 10

The electrode structure of claim 8, wherein said wall members are of metal and form a plurality of hexagonal cells, and said electrolyte-permeable member is a metal screen bonded to the edges of said wall members.

Claim 11

The electrode structure of claim 9 wherein said metal is selected from iron, steel, tantalum, and molybdenum.

Claim 12

An electrical energy storage device having positive and negative electrodes spaced from one another and in contact with a lithium-containing electrolyte, wherein the negative electrode is a composite electrode structure which comprises an alloy of lithium, silicon, and iron having the empirical formula Li x SiFe y , where x has a value from 1 to 5 and y has a value from 0.5 to 1, and wherein a current-collecting matrix supporting said alloy is in intimate contact therewith.

Claim 13

An electrical energy storage device having positive and negative electrodes spaced from one another and in contact with a lithium-containing electrolyte, wherein the negative electrode is a composite electrode structure which comprises an alloy of lithium, silicon, and iron having the empirical formula Li x SiFe y , where x has a value from 1 to 5 and y has a value from 0.5 to 1, and wherein a current-collecting matrix supporting said alloy is in intimate contact therewith.

Claim 14

The electrical energy storage device of claim 11, wherein x has a value from 4 to 5 and Fe has a value from 0.125 to 0.5.

Claim 15

The electrical energy storage device of claim 11, wherein said positive electrode contains a metal sulfide as the active material.

Claim 16

The electrical energy storage device of claim 11, wherein said electrolyte is a lithium-containing salt which is molten at the operating temperature of the device.

Claim 17

The electrical energy storage device of claim 14, wherein said lithium-containing electrolyte comprises a eutectic mixture of lithium halide and at least one other alkali metal halide.

Claim 18

The electrical energy storage device of claim 11, wherein x has a value from 4 to 5 and Fe has a value from 0.125 to 0.5, the positive electrode contains iron sulfide as its active material, and the lithium-containing electrolyte comprises a eutectic salt mixture of a lithium halide and at least one other alkali metal halide, said salt mixture being molten at the operating temperature of the device.